U.S. patent number 4,355,412 [Application Number 06/138,334] was granted by the patent office on 1982-10-19 for preset station selecting device in a radio receiver.
This patent grant is currently assigned to Nissan Motor Company, Limited. Invention is credited to Yasushi Kawakami.
United States Patent |
4,355,412 |
Kawakami |
October 19, 1982 |
Preset station selecting device in a radio receiver
Abstract
In a radio receiver which is electrically tuned to a
broadcasting frequency, a preset station selecting device having a
memory, a first circuit which previously writes a broadcasting
frequency into the memory when it receives a write selection and
write command, and a second circuit which reads the broadcasting
frequency out of the memory and sets the frequency in the receiver.
The station selecting device further includes a switch which in
turn includes a switchable member which has two switched positions.
This switch gives a write selection/write command to the first
circuit when the switchable member is at one switched position, and
a read command to the second circuit when the switchable member is
at the other switched position.
Inventors: |
Kawakami; Yasushi (Tokyo,
JP) |
Assignee: |
Nissan Motor Company, Limited
(JP)
|
Family
ID: |
26386538 |
Appl.
No.: |
06/138,334 |
Filed: |
April 8, 1980 |
Foreign Application Priority Data
|
|
|
|
|
Apr 10, 1979 [JP] |
|
|
54-46433[U] |
Apr 16, 1979 [JP] |
|
|
54-49393[U] |
|
Current U.S.
Class: |
455/175.1;
200/339; 200/6R; 365/189.15; 365/189.16; 455/158.1; 455/182.1;
455/186.1; 455/186.2 |
Current CPC
Class: |
H03J
5/0281 (20130101) |
Current International
Class: |
H03J
5/02 (20060101); H03J 5/00 (20060101); H04B
001/16 () |
Field of
Search: |
;455/170,175,177,185,186
;365/189 ;200/6R,6B,6BB,6BA,291,318,339 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1208849 |
|
Oct 1970 |
|
GB |
|
1363048 |
|
Aug 1974 |
|
GB |
|
1416532 |
|
Dec 1975 |
|
GB |
|
1435697 |
|
May 1976 |
|
GB |
|
1471712 |
|
Apr 1977 |
|
GB |
|
1518368 |
|
Jul 1978 |
|
GB |
|
1518712 |
|
Jul 1978 |
|
GB |
|
1553366 |
|
Sep 1979 |
|
GB |
|
Primary Examiner: Ng; Jin F.
Claims
What is claimed is:
1. In a radio receiver which is electrically tuned to a
broadcasting frequency, a preset station selecting device
comprising:
a memory;
means for previously writing a broadcasting frequency into the
memory when it receives a write selection and write command
signal;
means for reading the broadcasting frequency out of the memory and
electrically setting this frequency in the receiver;
a switch including a switchable member which has two switched
positions, the switch being adapted to give a write selection and
write command signal to the writing means when the switchable
member is at one switched position, and being adapted to give a
read command signal to the reading means when the switchable member
is at the other switched position;
the switchable member being supported at a pivotal point in the
switch; the switch comprising two parallel electrically insulating
legs extending backward from a back of the switchable member, one
on each side of the pivotal point, an insulating plate comprising
thereon two separate groups of electrical contacts which are
disposed so as to align with the two legs respectively, two
electrically conductive contact members each disposed between and
aligning with one insulating leg and a corresponding group of
contacts made of electrically conductive rubber and normally
separated from said corresponding group of electrical contacts;
one of said insulating legs of the switchable member being provided
with a recess in one side thereof; and
a locking roller engaging with the recess at said one switched
position of the switchable member.
2. The preset station selecting device of claim 1, wherein the
switch is further provided with an insulating resilient member
attached to the electrically conductive contact members, the
insulating resilient member being positioned between the
electrically conductive contact members and the insulating legs,
and the insulating member being adapted to be pressed by the
switchable member so as to push the contact members to be contacted
against their corresponding groups of electrical contacts.
3. The preset station selecting device of claim 1, wherein the
other insulating leg is longer than the said one leg which is
provided with the recess.
4. In a radio receiver which is electrically tuned to a
broadcasting frequency, a preset station selecting device
comprising:
a memory;
means for previously writing a broadcasting frequency into the
memory when it receives a write selection and write command
signal;
means for reading the broadcasting frequency out of the memory and
electrically setting this frequency in the receiver;
a switch including a switchable member which has two switched
positions, the switch being adapted to give a write selection and
write command signal to the writing means when the switchable
member is at one switched position, and being adapted to give a
read command signal to the reading means when the switchable member
is at the other switched position;
the switchable member being supported at a pivotal point in the
switch; the switch comprising two parallel electrically insulating
legs extending backward from a back of the switchable member, one
on each side of the pivotal point, an insulating plate comprising
thereon two separate groups of electrical contacts which are
disposed so as to align with the two legs respectively, two
electrically conductive contact members each disposed between and
aligning with one insulating leg and a corresponding group of
contacts made of electrically conductive rubber and normally
separated from said corresponding group of electrical contacts;
the switch further comprising a lock member extending backwards
from the back of the switchable member on the side of one of the
insulating legs away from the pivotal point, and the plate having a
hole in which the lock member is locked when the switchable member
is moved to said one switched position.
5. The preset station selecting device of claim 4, wherein the lock
member has a triangular locking portion attached at one side of a
free end portion of the lock member and having an entry angle and a
release angle different from each other, so that the forces exerted
on the switchable member in each switching case provide different
tactual sensations.
6. In a radio receiver which is electrically tuned to a
broadcasting frequency, a preset station selecting device,
comprising:
a memory;
a switch having a particular number and including a switchable
member which has two switched positions;
write selection and write command means responsive to one of said
two switched position of said switchable member for giving a write
selection and write command signal;
a clock pulse generator responsive to the write selection and write
command signal for generating clock pulses;
read command means responsive to the other of the two switched
positions for giving a read command signal;
an input discriminator responsive to the presence of the clock
pulses for putting the memory into a write enable situation,
responsive to the write selection and write command signal for
producing a signal representing the number of the switch;
a key number selector responsive to the signal representing the
number of the switch for specifying a write address in the memory;
and
a read/write discriminator responsive to the presence of the clock
pulses for writing a tuned frequency information in the specified
address, and responsive to the absence of the clock pulses for
reading the frequency information out of the memory.
7. The preset station selecting device of claim 6, wherein the
switchable member is supported at a pivotal point in the switch;
wherein the switch comprises two parallel electrically insulating
legs extending backward from a back of the switchable member, one
on each side of the pivotal point, an insulating plate comprising
thereon two separate groups of contacts made of electrically
conductive rubber which are disposed so as to align with the two
legs respectively, two electrically conductive contact members each
disposed between and aligning with one insulating leg and a
corrresponding group of electrical contacts and normally separated
from said corresponding group of electrical contacts.
8. The preset station selection device of claim 7, wherein the
switch further comprises a lock member extending backwards from the
back of the switchable member on the side of one of the insulating
legs away from the pivotal point, and wherein the plate has a hole
in which the lock member is locked when the switchable member is
moved to said one switched position.
9. The preset station selecting device of claim 8, wherein the lock
member has a triangular locking portion attached at one side
thereof to a free end portion of the locking member, and having an
entry angle and a releasing angle different from each other, so
that the forces exerted on the switchable member provide different
tactual sensations.
10. The preset station selecting device of claim 7, wherein one
insulating leg of the switchable member is provided with a recess
in one side thereof, and further comprising a locking roller
engaging with the recess at said one switched position of the
switchable member.
11. The preset station selecting device of claim 10, wherein the
other insulating leg is longer than said one leg which is provided
with the recess.
12. The preset station selecting device of claim 7, wherein the
switch is further provided with an insulating resilient member
attached to the electrically conductive contact members, the
insulating resilient member being positioned between the
electrically conductive contact members and the insulating legs,
and the insulating member being adapted to be pressed by the
switchable member so as to push the contact member to be contacted
against their corresponding groups of electrical contacts.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a radio receiver, and more
particularly to a preset station selecting device for use in a
radio receiver.
Recently, radio receivers have come into wide use which can be
electronically tuned to broadcasting frequencies using a
phase-locked loop. Especially, in radio receivers used in
automotive vehicles, in addition to the electronic tuning function,
a station selecting device has come into practical use which uses
tuning frequency information stored in a memory for tuning into
broadcasting stations. This device has a function to write the
frequency information relating to a selected station into a memory,
and to read the information out of the memory, in order to select
the broadcast station. Commands for these operations are sent by
switching operations. This station selecting device is so
constituted that writing in the memory is effected by receiving a
write-ready command and a write command. Thus two switches are
needed, one for making the memory ready for writing, and another
for actually writing frequency information into the memory. In
presetting the radio receiver, these two switches are both
operated.
When an automotive vehicle is making a long trip, the broadcasting
stations which can be received are liable to vary from place to
place. In this case, a new station cannot be received, using the
old tuning frequency used so far, although the energy of the new
broadcasting frequency may be sufficiently strong. When the new
station is desired to be received in automatic selection mode, its
frequency must be newly set.
In such a case, two switches must be operated, one for starting
preparation for writing, and the other for starting actual writing,
in the prior art devices.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a
preset station selecting device in a radio receiver, wherein a
single switch gives at one switched position a command to prepare
for writing, and/or to actually write, a broadcasting frequency
into a memory and gives at another switched position another
command to read the frequency out of the memory, thereby
simplifying a selecting operation of the broadcasting
frequency.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention
will be more apparent from the following description, taken in
conjunction with the accompanying drawings, which are given by way
of illustration only and not limitative to the present
invention.
In the drawings:
FIG. 1 is a block diagram of a radio receiver incorporating a
preset station selecting device according to one embodiment of the
present invention;
FIG. 2 is a schematic illustration of the operation panel of the
receiver;
FIG. 3 is a sectional view of a preset station selecting switch
shown in FIG. 1;
FIG. 4 is a possible modification of the switch;
FIG. 5 is a fragmentary view of a lock member of the FIG. 4
modification; and
FIG. 6 is a second possible modification of the switch.
Throughout the drawings, reference numerals which are the same
except for suffixes "a" and "b", designate corresponding members in
the several embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and particularly to FIG. 1, a radio
receiver which incorporates a preset station selecting device
according to the present invention is shown, generally designated
by reference numeral 10. A broadcast wave received by an antenna 12
is introduced into a radio frequency tuner and amplifier circuit
14. The broadcasting frequency of the wave is then transformed in a
mixer 16 to an intermediate frequency. A conventional phase-locked
oscillator 17 includes a phase-locked loop which sets a tuning
frequency and a local oscillating frequency for the circuit 14 and
the mixer 16, respectively. The intermediate frequency from the
mixer 16 is introduced through an intermediate frequency amplifier
18 and an amplitude limiter 20 to a detector 22 where the
intermediate frequency is changed to a low frequency signal, which
is amplified by an audio-frequency amplifier 24 and which is
supplied to a speaker 26.
The phase-locked oscillator 17 includes a crystal oscillator 170, a
phase comparator 172, a low-pass filter 174, a voltage-controlled
oscillator 176, a frequency divider 178, and a loop 180 which
connects these elements. The tuning frequency for the circuit 14
and the local oscillating frequency for the mixer 16 are determined
by the frequency divisor in the frequency divider 178.
An automatic station finding circuit 28 includes an input
discriminator 280 which senses whether the frequency of the
phase-locked oscillator 17 should be increased when a tuning key 32
is pressed down, a clock pulse generator 282 which is started or
stopped by the output of the discriminator 280, and a divisor value
setting register 284 whose preset numerical value is incremented or
decremented by clock pulses from the clock pulse generator 282. The
value in the register 284 is fed, through a bus 286, a buffer 288
and a bus 290, to the divider 178, so as to be used as the divisor
N therein. The input signal to the intermediate frequency amplifier
18 is also supplied to the input discriminator 280. When this input
signal exceeds a predetermined level, the discriminator 280 causes
the clock pulse generator 282 to stop sending clock pulses, in
which case, the content of the register 284 is sent through the
buffer 288 and set as the divisor N in the divider 178.
On the other hand, a preset station selection circuit 30 includes a
clock pulse generator 300, an input discriminator 302 which detects
which of a write selection/write command circuit 38 and a read
command circuit 40 has been operated, a key number selector 304
which sends the number of an operated preset station selector key
36 as address information, a read/write discriminator 306, and a
random access memory (RAM) 308 which stores frequency information
fed through a bus 42.
Referring to FIG. 2, an operation panel, generally designated by
44, of the radio receiver includes the key 32, a display 46 which
indicates the frequency of a selected station, and a plurality of
preset station selection keys 36 which send a write selection/write
command, or a read command. As shown in FIG. 3, each key 36 is a
part of a corresponding switch 48, which includes a pivot 480
secured to a fixed frame 482 and by which the key is pivotally
supported, the key being normally held at a neutral position by a
biasing member, not shown. The preset key is provided with two
parallel legs 484 and 486 made of an electrically insulating
material and protruding backwards from the back of the key. Each
switch further includes two electrically conductive contact members
488 and 490, which are made of electrically conductive rubber and
which face the legs 484 and 486, and two groups of electrical
contacts 492 and 494 formed on a printed circuit board 496. These
two groups of electrical contacts 492 and 494 are electrically
connected by the corresponding contact members 488 and 490, when
contacted thereby. Thus, when the preset key 36 is pressed in the
direction shown by the arrow P.sub.1 in FIG. 3, it is rotated up to
the position shown by the phantom line 36', so that the leg 484
presses the contact member 488 against the contacts 492, thereby
connecting these contacts. This causes a write selection/write
command to be sent, for setting frequency information in the RAM
308 of the preset station selection circuit 30. When the key is
pressed in the opposite direction shown by the arrow P.sub.2, the
contacts 494 are closed by the conductive contact member 490, which
is pressed by the leg 486, whereby a read command to read the
frequency information set in the RAM 308 is sent.
In operation, the tuning key 32 may be automatically or manually
operated. The input discriminator 280 discriminates whether the
sweep frequency should be increased and, if so, starts the clock
pulse generator 282. The clock pulses from the generator 282, once
started, change the value preset in the register 284 either up or
down. The count in the register 284 is sequentially set as "N" in
the frequency divider 178 of the phase-locked oscillator 17 through
the buffer 288, so as to vary the oscillating frequency from the
oscillator 17, on the basis of the ratio "1/N", using the
phase-locked loop structure. Thus the tuning and local oscillating
frequencies for the tuning circuit 14 and the mixer 16 are varied
over the respective ranges of frequency.
This varying of the oscillating frequency causes the receiver to be
tuned to the broadcasting frequency. When the level of the received
signal at the input stage of the intermediate frequency amplifier
18 exceeds a predetermined value, this input signal is applied as a
selection stop signal to the input discriminator 280 of the
automatic station finding circuit 28 to stop the clock pulse
generator 282. Thus the content of the register 284 is set at the
value of "N" when the oscillating frequency of the oscillator 17
has tuned to the broadcasting frequency with the result that the
oscillating frequency from the oscillator 17 is locked to a
frequency determined by the divisor which is the value in the
register 284. Accordingly the automatic station finding is
completed.
Under these circumstances, presetting of the broadcast frequency,
using the preset station selection circuit 30, is carried out as
follows. First, the preset key 36 is pressed in the direction of
write selecting and writing, i.e. in the direction of the arrow
P.sub.1 in FIG. 3. Then the write selection/write command circuit
38 sends a command to the clock pulse generator 300 and the input
discriminator 302 to cause the clock pulse generator 300 to
generate clock pulses and send the same to the input discriminator
302 to put the RAM 308 into a write enable situation. At the same
time, the input discriminator 302 gives the number of the pressed
key 36 to the key number selector 304, thereby causing the same to
specify a write address in the memory 308. The read/write
discriminator 306 determines that a write command has been sent to
the RAM 308 when the clock pulse generator 300 has already been
started. This causes the tuning frequency information, i.e. the
divisor value set in the register 284, to be written through the
bus 42 in the address corresponding to the pressed key.
As will be seen from the above, the selection device according to
the present invention effects write selecting and writing of the
frequency information given during driving, into the RAM 308, by
only one operation of depressing the corresponding preset key
36.
The reading of the frequency information, once it is preset in the
memory, is effected as follows. When a preset key 36 is depressed
as shown by the arrow P.sub.2 in FIG. 3, a read command is fed to
the input discriminator 302, at which time, however, the clock
pulse generator 300 is not started. Thus the read/write
discriminator 306 determines that the command is for reading. This
causes the frequency information stored in the RAM 308 at the
address specified by the key number selector 304 to be read out of
the RAM 308 and to be set through the buffer 288 in the frequency
divider 178 of the phase-locked oscillator 17. Thus the
phase-locked oscillator 17 is locked in oscillating frequency to
the frequency read from the RAM 308, thereby allowing the reception
of the desired broadcasting frequency.
Referring to FIG. 4, a modification of the switch used in the
present invention is shown at 48a, which is of substantially the
same structure as the switch of FIG. 3, except that the switch has
a lock member 498a extending backwards from the back of a key 36a,
and a hole 500a provided in the printed circuit board 476a.
When the key 36a is pressed from its neutral position in the
direction shown by the arrow P.sub.1, in order to effect writing,
it rotates about the pivot 480a thereby causing the leg 484a to
contact the conductive contact member 488a against the contacts
492a, with the result that the contacts 492a are connected, and the
selected frequency is written into the memory, as in the first
embodiment of FIGS. 1 to 3. At this time, the lock member 498a is
engaged in the hole 500a in the board 496a and locked there. Under
these circumstances, the key remains in depressed position, thereby
providing a tactual sensation that the frequency is written into
the memory. Further, it is possible to visually and tactually
ascertain which of the keys 36a is operated.
The locked down key 36a may be released by pressing the key in the
direction of the arrow P.sub.2, whereby the lock member 498a is
disengaged from the hole 500a and returned to its neutral position.
In this modification, it is so arranged that the operating force
P.sub.1 required to press the key for locking differs from the
force P.sub.2 required to release the key for returning it to the
neutral position. To this end, the lock member 498a has a
triangular end portion 502a attached at one side thereof to a free
end portion of the lock member, as is best illustrated In FIG. 5.
The triangular end portion 502a has two different base angles, i.e.
the gradients of the two free sides vary with respect to the
locking direction, thus functioning as an entry angle .alpha. and a
release angle .beta., respectively. For example, it is so arranged
that P.sub.1 =500 to 600 grams and P.sub.1 =70 to 100 grams,
thereby providing sufficient discrimination between the two
operating tactual sensations.
On the other hand, when the key 36a in the neutral position is
depressed in the direction of the arrow P.sub.2, the leg 486a
causes the conductive contact member 490a to contact the contacts
494a and connect the same, thereby reading the memory. When this
reading of the frequency out of the memory is effected, the
broadcast whose frequency is read is obtained as received sound.
Accordingly, it is unnecessary to confirm the reading of the
frequency in any visual or tactual manner. Thus no locking means is
provided for the reading operation.
Referring to FIG. 6, a second modification of the switch used in
the present invention is shown, which is of the same structure as
that of FIG. 3, except that a leg 484b is provided with a recess
504b on one slanted side thereof, the other leg 486b is longer than
the leg 484b, contact members 488b and 490b are attached to an
electrically insulating contact member 506b of rubber, and a roller
508b pivoted at a fixed point is provided for engaging in the
recess 504b in the leg 484b and rolling on the slanted side of the
leg 484b.
In operation, when the frequency is to be written in the memory,
the key 36b is pressed in the direction of the arrow P.sub.1, and
is locked by the engagement of the key recess 504b on the roller
508b, at which time the operating force required is determined by
the angle of the slope of the leg 484b in rolling contact with the
roller 508b, and the positional relationship between the roller and
the recess. The operating force required for depressing the key 36b
in the direction of the arrow P.sub.2 is determined by the
thickness of the insulating contact member 506b and the thickness
of the conductive contact member 490b. Thus the operating force
acting in the direction of the arrow P.sub.1 is larger by the
resistance force occurring between the leg 484b and the roller 508b
than the operation force acting in the direction of the arrow
P.sub.2 thereby providing two different tactual sensations due to
the switching forces, respectively.
In the two above modifications, a tactual sensation from the
switched key available at the one switched position allows to check
that a process has been performed of which the results, i.e. the
writing of frequency information into the memory, do not appear
outside the apparatus. Thus, especially, in the case of a car radio
receiver, a visual check is unnecessary.
In the above embodiment and modifications, the switches have been
shown as having a seesaw structure, in which a key is turned about
a pivot for switching. However, instead of these switches, a
conventional push button switch, a conventional toggle switch,
etc., may be used. Any locking means for the key may be used which
is suitable for the structure of a switch to be used. In order to
provide a discrimination between the two operating forces, a
conventional spring can be used. The above embodiment and
modifications have been described and illustrated as being
concerned with the preset station-selecting switch, but are
applicable to other operating switches such as, for example,
automatic station-selecting switches.
Although the present invention has been shown and described with
reference to a particular embodiment and modifications thereof, and
with reference to the illustrative drawings, it should not be
conceived of as limited thereto; various alternatives, omissions,
and modifications to the form and the content of any particular
embodiment could be made therein, without departing from the spirit
of the invention, or from its scope, and it is therefore desired
that this scope should be defined, not by any particular features
of the shown embodiment and modifications (which are given, as were
the drawings, for the purposes of elucidation only), but solely by
the accompanying claims.
* * * * *